<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<script>
			function checkWin(){
				document.write(myWindow.name);
			}
		</script>
	</head>
	<body>
			<script>
				myWindow = window.open('','mywindowfRAME','width=200,height=100');
				myWindow.document.write("this is 'mywindow'");
			</script>
		
		<input type="button" value="check" onclick="checkWin()">
	</body>
</html>
